Lease Commitments - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Lease, Cost [Line Items]
Operating lease cost:		$ 4,337
Amounts capitalized	$ (267)	(513)
Operating lease cost:	5,009	3,824
Financing lease cost:
Amortization of right-of-use assets	2,542	2,093
Interest on lease liabilities	297	234
Amounts capitalized	(2,023)	(1,690)
Total financing lease expense	816	637
Variable lease expense	360	262
Short-term lease expense	216	151
Total lease expense for the period	6,401	4,874
Battery Storage Leases
Lease, Cost [Line Items]
Operating lease cost:	2,947
Other Operating Leases
Lease, Cost [Line Items]
Operating lease cost:	2,329
PNM
Lease, Cost [Line Items]
Operating lease cost:		3,908
Amounts capitalized	(35)	(160)
Operating lease cost:	4,971	3,748
Financing lease cost:
Amortization of right-of-use assets	1,218	1,008
Interest on lease liabilities	144	122
Amounts capitalized	(841)	(690)
Total financing lease expense	521	440
Variable lease expense	360	262
Short-term lease expense	204	147
Total lease expense for the period	6,056	4,597
PNM | Battery Storage Leases
Lease, Cost [Line Items]
Operating lease cost:	2,947
PNM | Other Operating Leases
Lease, Cost [Line Items]
Operating lease cost:	2,059
TNMP
Lease, Cost [Line Items]
Operating lease cost:		429
Amounts capitalized	(232)	(353)
Operating lease cost:	38	76
Financing lease cost:
Amortization of right-of-use assets	1,316	1,064
Interest on lease liabilities	152	111
Amounts capitalized	(1,182)	(1,000)
Total financing lease expense	286	175
Variable lease expense	0	0
Short-term lease expense	6	0
Total lease expense for the period	330	$ 251
TNMP | Battery Storage Leases
Lease, Cost [Line Items]
Operating lease cost:	0
TNMP | Other Operating Leases
Lease, Cost [Line Items]
Operating lease cost:	$ 270